So there is the Simple and Complex HUD options in YSFlight, that you can toggle between when activated. Conversely you have Instrument Panels with steam-gauge style instruments.If you wanted to go no HUD, you would likely have to do some combination of instrument panels and turning the HUD OFF.

As for modifying the HUD, you only have the two options. To my knowledge there is no way to edit what is seen (aside from TAS or CAS) in the HUD

Another option you might consider, is have a static crosshair on the aircraft itself as part of the aircraft model.

My own Black Dragon F/A-18's have a blank cockpit model file, and a blank instrument panel (.ISP?) file referenced in the DAT file, and "use instrument panel" set to TRUE. This way, when you start flight, you're greeted with an empty cockpit without any instruments or hud. To turn the hud on, you just set the ingame option "always show hud" to true using the CTRL key menu. You could do a similar thing, but just have the crosshair as part of the model file if that's what you are after. Some things on the hud you could even animate - I have an animation panel for the burners, stabs and slats etc. on the aforementioned model in the cockpit.

In short - the hud is hard coded in the game, but you can be creative and partially build your own.

I am an accountant working full-time (and some). I'm not here as often as I would like to be. Send a message if you need me. There are a few people in the community who can get in contact with me urgently if you need - don't be afraid to ask. I just don't check here as frequently as I used to. Sorry!

IQ 200 response to the problem right there, never even considered doing that.

Care to share a screenshot of that? I'm quite curious now.

I am an accountant working full-time (and some). I'm not here as often as I would like to be. Send a message if you need me. There are a few people in the community who can get in contact with me urgently if you need - don't be afraid to ask. I just don't check here as frequently as I used to. Sorry!

AND, check out the crosshairs on my P-40B. If you click F1 you go to the ex-camera position lined up with the crosshairs. Click 'reserve thrust' button when firing to see the muzzle flash for extra kick.